A top security official, speaking on condition of anonymity, said a videotape had been received by the authorities on Thursday night Pakistan time, "showing Pearl in captivity and then his execution." He said the footage "appears to be genuine and without any doubt." Some press reports said the tape showed Pearl's throat being cut, while other reports said it showed him being beheaded.

The official said Gen. Pervez Musharraf had been shocked to learn of the tragedy and had ordered drastic action to be taken against the culprits.

Pearl went missing in Karachi on January 23, while investigating suspected links between the al Qaeda terrorist network and Richard Reid, the British national who allegedly tried to blow up an American airliner...